Subject matter of the invention is a vessel for reducing contamination in the treatment of liquids, said vessel having an inlet and an outlet opening; the latter opening can be closed in a special way.
In many fields of application, the treatment of liquids requires particular care with respect to actively avoiding contamination which could adversely affect the environment. This applies particularly to noxious liquids, but also to liquids which are used or generated in the analysis of components. The treatment steps to prepare a sample liquid for an analysis are usually carried out in the same laboratory or even the same room as the analysis itself. The use of aerosols, for example, often leads to heavy contamination of the environment with sample components; this in turn interferes with the analysis of components of other samples. An erroneous result can have terrible consequences for the patient, especially when analyzing components in the field of medical and clinical diagnostics.
Analyses that are based on the detection of nucleic acids in a sample have recently been introduced as diagnostic tools owing to their relatively high specificity. These tests are a considerable technical challenge since the contents of nucleic acids and especially the nucleic acids to be detected is a very small one while nucleic acids having similar sequences and other components which may interfere with the determination are also present in the same sample. Experience has shown that amplification procedures which have recently become more and more popular are used to produce a multitude of identical nucleic acids dependent on the presence of certain nucleic acid sequences to be tested; this greatly improves the sensitivity of the test, allowing to even detect individual nucleic acids. The risk involved in the possible high sensitivity of the tests is that contamination of other samples even with only one single nucleic acid from the environment can cause, i.e. simulate, a positive result. When using nucleic acid tests, it is therefore necessary to avoid in a particularly effective manner already the generation of contamination, i.e. the release of nucleic acids from a sample or a reaction mixture into the environment.
When preparing samples for the analysis of components, especially nucleic acids, methods have recently been used where the sample liquid and the components to be analyzed contained therein are subject to a treatment in the vessel wherein liquid is introduced into the vessel through an inlet opening and removed again through an outlet opening after undergoing one or several treatment steps. Such vessels are commercially available in the form of columns containing materials for the separation of components from the liquid, an example being the QlAamp Kit manufactured by Qiagen. These vessels are contained in another vessel, so that liquid which may leak is released into this second vessel and not into the environment. This kind of liquid treatment is, however, complex and requires a corresponding second vessel. Moreover, these vessels are used in the centrifuges in order to transfer the liquid into the second vessel.
DE-A-4020442 describes a system wherein a rigid seal which seals the surface of blood sample vessels is pierced open with the aid of device that is equipped with a needle. Said needle can be covered by a protective cap. A separate tool is, hence, necessary to open and close the vessel.
DE-A-4124577 describes a reagent bottle whose bottom side is closed with a screw cap.
U.S. Pat. No. 3,706,305 describes a container where liquids can be transported with the aid of needles which pierce a membrane.
U.S. Pat. No. 3,601,152 discloses a valve where an elastic piece is completely removed from a projection. Said projection has no lateral openings.
The use of such a valve to avoid contamination has not yet been described.
DE-C-4214634 describes a pipetting aid to absorb liquids, said aid comprises an elastic hollow body and several valves for the in- and outlet of air.
DE-C-4204554 describes an ampoule for liquids where an inlet opening is opened by piercing a plastic membrane using a tip that is integrated in a funnel. The removal of liquid cannot be accomplished by applying pressure differences
DE-A-3139702 describes a vessel for handling paste-like sample material. The outlet openings are closed by means of snap-tops.
U.S. Pat. No. 4,956,298 describes a separation or reaction column that can be emptied via centrifugation. The outlet opening is closed with the aid of a snap-top that has to be mechanically removed.
U.S. Pat. No. 3,799,426 describes a container which is provided with a projection at its top; said projection prevents the vessel from falling through an apertured plate.
EP-A-0 561 003 describes a vessel for receiving liquids wherein the liquid is passed through several membranes when entering the vessel. An elastic seal of the outlet opening is not proposed.
EP-A-0 182 370 describes a blood storage device having a blood intake tube; said blood intake tube can be tightly sealed with a cap that is placed on the tube. An opening with the aid of pressure differences is not proposed.
U.S. Pat. No. 5,139,742 describes a device which comprises two pieces that can be brought into a position to allow the passage of liquid. The outlet opening in this element is not elastically closed with the aid of another element. The opening of the liquid passage is not accomplished with the aid of pressure differences.
DE-A-4021355 describes a blood removal device that is closed with the aid of a pierceable elastic plate. The device is opened with the aid of a hollow needle. However, the closure is provided to allow liquid to be taken into the device. To accomplish this, a vacuum is generated via another opening.
DE-A-2442149 describes a vessel for removing blood followed by a centrifugation procedure where the outlet opening is closed with the aid of a stopper. In order to open the outlet opening, the stopper must be manually removed.
DE-A-2328718 describes a disposable syringe where a screw cap is used to close an outlet opening.
DE-A-1541115 describes a disposable syringe where a semi-spherical cap is used to close the inlet opening.
U.S. Pat. No. 5,003,988 describes an apparatus for the detection of biological substances where liquid is pressed through a cylindrical opening.
DE-a-3639949 describes a method of separating long-chain nucleic acids with the aid of a filter material where the sample is made to pass through this filter material. The device used is a cartridge that is not opened by applying pressure.
U.S. Pat. No. 5,221,483 describes a device for filtering liquids wherein the liquid is passed through a porous filter and/or membranes. Inlet or outlet openings are not opened by applying pressure.
Leonhardt et al. (Amicon Biosolutions, 4/1994, pp 2-7) describe a system for the ultra-filtration of liquids wherein the liquid is transported across a filter by means of centrifugation.
Quiagen News, No. 1/94, pp 1-20, describe a system where liquids can be drawn through vessels. The outlet openings of these vessels can, however, not be reversibly opened or closed. Said literature reference also describes a vessel for cleaning nucleic acids wherein the liquid is passed through a filter material by means of centrifugation. Again, the outlet opening is not opened by applying pressure.
The latter vessel is also described in Quiagen News 2/94, pp 1-14.
It was, hence an object of the present invention to improve currently known methods for treating liquids by providing a new vessel.